1. Field of the Invention
The present invention relates to a length-variable magazine for small guns wherein the length of the magazine can be extended or contracted for loading a number of cartridges therein.
2. Description of the Prior Art
Various types of magazines are well known in the art. For example, conventional M16 rifles have a 20-cartridge loading type magazine and a 30-cartridge loading type magazine and these two types of magazines are separately produced.
In the case of such 30-cartridge loading type magazine, a cartridge is shaped such that a bullet is small in its diameter, and a shell having the detonating cap has a larger diameter compared with the bullet, while the lower portion of such magazine is gently curved in order to ease the actuation of a spring. Such magazine is not of a variable form but their outer structure is fixedly formed. Therefore, there is the disadvantage that such magazine has to be carried with its fixed structure regardless of the actual cartridge-loading capability.
In the case of the 30-cartridge loading magazine, even if a soldier wants that only 10 or 20 cartridges are loaded in the magazine, the soldier always has to use the 30-cartridge loading magazine which has a fixed bulk. Furthermore, in a battle field, a soldier has to carry 6 or 7 magazines. Therefore, the total volume of the magazines can give a severe impediment to the activities of the soldier with the ultimate result that an adverse effect is given to the combat ability of the soldier.
Also, in the case of the 30-cartridge loading magazine, it is difficult in manufacture because of the curved shape of the magazine as well as giving difficulties in carrying it. Due to the limitation of the restoring ability of the spring, the 20-cartridge loading magazine can actually accommodate only about 17 or 18 cartridges while the 30-cartridge loading magazine can actually accommodate only about 26 or 27 cartridges. Therefore, the remaining cartridges which are failed to be loaded have to be separately carried or discarded away, thereby aggravating the economic feature.